O (.o)
.o file signature | application/octet-stream
Executable and Linkable Format (ELF) is a binary file format created by UNIX System Laboratories and now maintained as part of the System V Application Binary Interface. It is used for executable programs, shared libraries, object files, and core dumps on Unix-like operating systems, including Linux and many embedded systems. ELF files are generally safe to handle, though malicious binaries can execute code if run; the format has largely replaced earlier legacy object formats.
Magic Bytes
Offset 0
7F 45 4C 46
Sources: Wikipedia
Extension
.o
MIME Type
application/octet-stream
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .o files in Python
def is_o(file_path: str) -> bool:
"""Check if file is a valid O by magic bytes."""
signature = bytes([0x7F, 0x45, 0x4C, 0x46])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .o files in Node.js
function isO(buffer: Buffer): boolean {
const signature = Buffer.from([0x7F, 0x45, 0x4C, 0x46]);
return buffer.subarray(0, 4).equals(signature);
}How to validate .o files in Go
func IsO(data []byte) bool {
signature := []byte{0x7F, 0x45, 0x4C, 0x46}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
/api/v1/o
curl https://filesignature.org/api/v1/o
See the full API documentation for all endpoints and parameters.
Related Formats
Frequently Asked Questions
What is a .o file?
A .o file is identified by the magic bytes 7F 45 4C 46 at byte offset 0. Executable and Linkable Format (ELF) is a binary file format created by UNIX System Laboratories and now maintained as part of the System V Application Binary Interface. It is used for executable programs, shared libraries, object files, and core dumps on Unix-like operating systems, including Linux and many embedded systems. ELF files are generally safe to handle, though malicious binaries can execute code if run; the format has largely replaced earlier legacy object formats.
What are the magic bytes for .o files?
The magic bytes for O files are 7F 45 4C 46 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .o file?
To validate a .o file, read the first bytes of the file and compare them against the known magic bytes (7F 45 4C 46) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .o files?
There is no officially registered MIME type for .o files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .o files?
O (.o) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.